Hibiscus shrubs do a great job of screening from spring through fall and fill the garden with flowers in the summer. Most of them mature 5-8' tall. Viburnums are one of my favorite plants. Easy to grow and beautiful flowers and fall foliage. Opening Day Doublefile matures 5-10' x 5-8'. If you are wanting an evergreen, check out Sky High Juniper. Would a narrow tree work? If so, look for Standing Ovation Serviceberry and Parkland Pillar Birch.
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